Insomniacs, Let There Be Light

If you’re prone to insomnia when it’s chilly outside, the problem may have to do with too little exposure to daylight in the colder months of the year. Working in well-lit conditions and using a light box may help to relieve your insomnia symptoms.

Use a light box early in the morning or in the evening, depending on your insomnia symptomsEvery November I hear increasing numbers of complaints about insomnia. Some people say they feel sleepier in the evening, go to bed early, and wake up at 3 a.m., unable to get back to sleep. Others toss and turn for hours before falling asleep only to oversleep their alarm clocks.

If you’re prone to insomnia when it’s chilly outside, the problem may have to do with too little exposure to daylight in the colder months of the year. Working in well-lit conditions and using a light box may help to relieve your insomnia symptoms.

A new meta-analysis suggests that bright light may be an effective form of therapy for insomnia all year round. But the effectiveness will depend on several things, including the timing of the light exposure and the intensity of the light. Here’s more about it.

A Gold Standard for Night Owls and Early Birds

The use of bright light therapy to treat circadian rhythm disorders—situations involving a mismatch between a person’s preferred sleep time and the alternation of daylight and darkness—is now standard practice. Results of the meta-analysis back these practices up:

  • Night owls tend to fall asleep and wake up quite late, missing morning activities. Their body clocks run slow, completing a daily cycle every 25 to 26 hours. Treatment calls for use of a light box immediately on waking up. Early exposure to bright light shifts their sleep cycle to an earlier hour and helps synchronize their circadian rhythms to the 24-hour day.
  • Early birds are usually struggling to keep their eyes open after 8 p.m. Their body clocks run fast, completing a cycle every 23 to 23.5 hours. The usual advice to early birds is to use the light box in the evening to postpone sleep and tune their internal rhythms to the 24-hour day.

Circadian Rhythm Factors in Insomnia

Surprisingly, the meta-analysis offers even more support for the idea that bright light therapy can improve the sleep of insomniacs. This may be due in part to the design of the studies reviewed. But it also suggests there may be a circadian component in insomnia, an idea that has been around a while. “Circadian rhythm factors may be involved in insomnia in several ways,” sleep investigators Leon Lack and Richard Bootzin have written in textbook on treating sleep disorders.*

People with sleep onset insomnia—trouble falling asleep at the beginning of the night—may have a mild version of the night owl problem. Our body clocks may run a little bit slow, completing a cycle once every 24.5 hours (rather than every 24 or every 24.2 hours, which in humans is the estimated norm). In certain situations—reduced exposure to light; sleeping in on weekends; working evening shifts—our internal sleep–wake rhythm may move farther and farther away from the daily alteration of daylight and darkness, exacerbating our trouble falling asleep.

Likewise, older adults who are increasingly prone to nod off after dinner may wake up feeling wired at their usual bedtime and have a tough time returning to sleep. Or if they do succeed in sleeping through the night, like early birds, they may not be able to sleep past 3 in the morning.

Light Exposure: Time It Right

Light can have a phase-shifting effect on the circadian system and blocks secretion of melatonin, a hormone associated with the night. So bright light may be used to shift sleep to a slightly earlier hour (which may help sleep onset insomniacs) or to prolong wakefulness in the evening. But the light exposure has to come at the right time of day.

Sleep onset insomniacs (whose goal is to get to sleep more easily) will—like night owls—want to expose themselves to bright light immediately upon waking up in the morning. The human body is most sensitive to light when it’s least expected. So half an hour’s exposure to bright light emitted from a light box as you’re getting dressed, eating breakfast, and reading the paper will be much more helpful than a longer exposure to light delivered later in the morning.

Older insomnia sufferers prone to drifting off too early in the evening may be able to remain up and alert until later if—while they relax after dinner with a book or in front of the TV—they do so in a room flooded with light (or better yet, seated next to a light box, which emits a lot more light than standard lighting fixtures). Delaying bedtime may also help to consolidate sleep at night and possibly extend sleep a little later in the morning.

Higher Intensity Light for Better Results

Authors of the meta-analysis found that in the insomnia studies they analyzed, the higher the light intensity, the greater was the effect. So if you’re shopping for light boxes, pay attention to the intensity of light different products emit. A light box that delivers light at the intensity of sunlight (10,000 lux) will give you the biggest bang for your buck.

If you’ve used a light box, what effect (if any) has it had on your sleep?

* Leon Lack and Richard Bootzin, “Circadian Rhythm Factors in Insomnia and Their Treatment,” in Treating Sleep Disorders: Principles and Practice of Behavioral Sleep Medicine, ed. Michael Perlis and Kenneth Lichstein (Hoboken: Wiley, 2003), 305-34.

Insomnia or Delayed Sleep Phase Disorder?

Sometimes I hear from people whose sleep problem sounds more like a circadian rhythm disorder than insomnia. Laurel wrote that she’d always been a night owl. So she was taking sleeping pills to get to sleep at night.

But if her problem is due to a delayed or sluggish body clock—if what she has is delayed sleep phase disorder (DSPD)—she’d be better off with other types of treatment. Here’s more:

Night owls are better off with bright light therapy than sleeping pillsSometimes I hear from people whose trouble sleeping sounds more like a circadian rhythm disorder than insomnia. Here’s what Laurel wrote:

 

 

 

 

I have trouble sleeping virtually every night—it is not intermittent—and I always have. I was a poor sleeper as a child, staying up until very late (3 a.m. to 5 a.m.), then being exhausted during the next school day and napping in the afternoon . . . continuing the vicious cycle. This pattern has pretty much stayed the same throughout my adult life. It seems to run in the family, as my mother had awful insomnia, as does my sister.

Laurel was taking sleeping pills to get to sleep at night. But if her problem has mainly to do with her body clock—if what she has is delayed sleep phase disorder (DSPD)—she’d be better off with other types of treatment.

Symptoms of DSPD

DSPD symptoms are similar to the symptoms of people with sleep onset insomnia:

  • Trouble falling asleep at bedtime
  • Catastrophic thinking at night (related to how their inability to fall asleep will affect their performance or interpersonal functioning the next day)
  • Poor cognitive functioning in the daytime and irritable mood

But in one fundamental way, the symptoms associated with the two disorders are different. Sleep onset insomniacs are inclined to poor sleep regardless of sleep opportunity. People with DSPD, in contrast, can generally get a good night’s sleep when allowed to sleep during the hours of their choosing (as, for example, when they’re on vacation). Their sleep problem has mainly to do with timing. School and work obligations fit poorly with their internal circadian rhythms. The result is sleep loss, poor performance, and, over time, reduced life prospects.

How DSPD Develops

It begins in adolescence. Then, for unknown reasons, children experience a biological delay in their sleep pattern. This delay causes them to want to go to bed and get up later (which is why later school start times for middle and high school students makes so much sense).

Then, as people reach the age of 20 or so, most of us start shifting backward again to earlier preferred bed and wake times. But a small number of people don’t shift back. They become night owls, and their preference to stay up till 3 and in bed till 11 can persist into middle age and beyond.

Delayed Circadian Rhythms

What keeps people like Laurel running late? Two phase markers determine when we feel like sleeping and when we’re ready to wake up. Onset of melatonin secretion is one. Melatonin secretion is negligible during the daytime but high at night, starting about 1 to 2 hours before normal bedtime. Research has shown that melatonin secretion begins about 4 hours later in people with DSPD than in normal sleepers.

The second phase marker is core body temperature. We’re physiologically alert at times when our core body temperature is high and sleepy when it’s low. Normal sleepers’ body temperature is highest—and physiological alertness, greatest—in the evening from about 6 to 9 p.m. In people with DSPD, this temperature high occurs 2 to 6 hours later.

The lowest core body temperature in normal sleepers—when people are sleepiest— occurs around 5 a.m. Research has shown that the body temperature low occurs on average over 2 hours later in people with DSPD. No wonder they can sleep right through buzzing alarm clocks.

A Longer Circadian Period

Studies have also shown that people with DSPD have longer-than-normal circadian periods. The average circadian period in humans—the time it takes to complete a full cycle—is 24 hours 12 minutes. Exposure to sunlight corrects for the 12-minute delay and keeps most of us running on 24-hour days.

The body clock in people with DSPD tends to run slow, cycling once every 25 or even 26 hours. The 1- or 2-hour advance needed to bring them into sync with the 24-hour day is harder to accomplish, say sleep experts, and likely another cause of DSPD.

Treatments

The gold standard in treatment for people with DSPD is early morning bright light therapy combined with a melatonin supplement taken around dinnertime:

  • Bright light: The light source can be the sun or a light box that disseminates light at 10,000 lux. Light exposure should occur immediately upon waking up. Two-hour sessions are most effective.
  • Melatonin supplement: Phase advances are also larger when morning bright light therapy is combined with a melatonin supplement taken late in the afternoon or early in the evening. In a recent study, 0.5 mg of melatonin taken late in the afternoon and 30 minutes of bright light therapy in the morning produced 75% of the phase shift that occurred with the 2-hour light exposure.

Q&A: Should Night Owls Use Sleeping Pills?

Rob wrote to Ask The Savvy Insomniac complaining about insomnia and wondering if Belsomra might help.

Today’s blog post features his story and my response.

Rob wrote to Ask The Savvy Insomniac complaining about insomnia and wondering if Belsomra might help.

trouble functioning in the a.m. could indicate circadian rhythm disorder

I’ve had insomnia since my teens. Never could get to sleep before 2:30. And that’s when I’m lucky. Sometimes it’s 3:30 or 4.

I do everything I’m supposed to do. I work out at the gym every day. I have a few beers when I get home but that’s it. I use a blue light blocking app on my computer and anyway I’m usually off it by 11. But nothing I do changes the situation. I just don’t feel sleepy. No matter how sleep deprived I am, I feel wired.

When the alarm goes off at 7:20 I feel exhausted. Coffee doesn’t help. I fight to stay awake at the office and by the end of the week it’s a losing battle. Early morning meetings are the worst.

What saves me is being able to sleep in on weekends. That and sleeping pills. Ambien will sometimes put me to sleep by 1. So my question is: Do you think Belsomra could work for me?

Barking up the Wrong Tree

I’m no doctor, but I suspect that if Rob were to consult a sleep specialist, his diagnosis would not be insomnia disorder but rather delayed sleep phase disorder (DSPD). The symptoms he reports are classic:

  • a preference for going to sleep several hours later than normal
  • difficulty sleeping at more conventional times
  • feeling alert, not sleepy, at night
  • struggling to wake up and function in the morning
  • catching up on sleep on the weekends

Rob might not have a sleep problem if his work began at noon. But most jobs start earlier, and for people with DSPD, trying to function on a conventional schedule is a major ordeal. It can quickly lead to sleep deprivation and trouble meeting obligations. It limits prospects down the line.

A 25-Hour Circadian Period

We humans can’t choose our sleep time preferences. Whether you’re a night owl, an early bird, or somewhere in between depends on a mix of genetic factors. These preferences can be modified, though, and may also evolve with age-related changes.

Sleep experts have long suspected that people with DSPD have body clocks that run slow, taking longer to complete their daily cycle. While the average circadian period in humans is 24 hours 11 minutes, scientists have hypothesized that the period length in people with DSPD is closer to 25 hours.

The results of two recent studies confirm that circadian rhythms are quite a bit more delayed in people with DSPD than in normal sleepers:

  1. Investigators in Australia assessed study participants’ core body temperature rhythms over 78 hours and found that under conditions of a constant routine, DSPD patients’ temperature rhythms were delayed by about one hour a day. This suggests “that DSPD patients, on average, must advance their circadian rhythm by almost an hour each day to maintain stability of their sleep–wake cycle to the 24-hour world.”
  2. Using a similar, 30-hour study protocol, the same team found that melatonin secretion began almost 3 hours later in DSPD patients than in normal sleepers. While in normal sleepers the melatonin secretion began with a surge, in DSPD patients, it started out gradually.

No wonder people like Rob have trouble getting to sleep!

Therapies: Bright Light and Melatonin

The most effective treatment for night owls wanting to get to sleep sooner is not sleeping pills but rather bright light therapy. The light source can be the sun or a light box that disseminates light at 10,000 lux. Light exposure should occur first thing in the morning. The largest phase advances occur in sessions lasting for 2 hours.

Phase advances are also larger when morning bright light sessions are combined with a melatonin supplement taken late in the afternoon or around dinnertime. Combined with 0.5 mg of melatonin taken late in the afternoon, continuous exposure to bright light for 30 minutes early in the morning was found, in another recent study, to produce 75% of the phase shift that occurred with the 2-hour exposure.

But the bright light–melatonin regimen is not a cure for DSPD. Stop it and your circadian rhythms will revert to their natural cadence. This will also happen if you allow yourself to sleep in late on weekends. You’ll function best if you maintain the same sleep-wake schedule all 7 days of the week.

As for sleeping pills like Ambien and Belsomra, why assume the risks these pills confer when bright light therapy and melatonin supplements, which have few if any side effects, can work even better?

If you’re a night owl, have you tried bright light therapy and/or melatonin supplements? How have they worked?

Q&A: The Why’s of Winter Insomnia, and What to Do

If there’s a seasonal pattern to your insomnia, reduced light exposure could be the culprit. People in northerly latitudes are exposed to little daylight in the winter, and this can have a negative effect on circadian rhythms and worsen sleep.

lightboxWhy is it, an insomnia sufferer recently wrote to Ask The Savvy Insomniac, that my insomnia always seems to get worse in the winter? “Erratic” describes my sleep right now. Some mornings I wake up like a bear coming out of hibernation! It’s all I can do to haul myself out of bed. Then when I do get up I’m low on energy and my mind’s in a fog. Some nights I fall asleep early (and wake up as early as 3!), and other nights I can’t fall asleep till 1 or 2.

If there’s a seasonal pattern to your insomnia, reduced light exposure could be the culprit. People in northerly latitudes are exposed to little daylight in the winter, and this can have a negative effect on circadian rhythms and worsen sleep.

Absence of daylight can interfere with the normal rhythm of your body’s secretion of melatonin, a hormone under circadian control. Melatonin secretion typically begins about two hours before you fall asleep and ends at wake-up time. But melatonin is light sensitive. Without the benefit of early morning light, melatonin secretion may be prolonged, making you feel sleepy and less alert.

Absence of light in the evening, on the other hand, can cue melatonin secretion to start soon after dinner. You nod off early and then awaken too early in the morning.

Bright Light Therapy: What and How

The recommended treatment for seasonal sleep disorders involves a light box—bright fluorescent bulbs encased in a box with a diffusing screen. The box is designed to deliver light at the intensity of sunlight—10,000 lux—in a way that’s safe for the eyes, with a minimal amount of ultraviolet (UV) light.

When using a light box, set it on a table or a desktop so the light is aimed at you but you’re not looking directly into it. Use it while doing any stationary activity: reading, eating meals, working at the computer, watching TV.

Timing Is Important to Success

If your main complaint is oversleeping and feeling groggy in the morning, schedule sessions with the light box early in the morning when it’s still dark outside—say, at 6:30 a.m. Thirty minutes a day is sufficient for many users (and is generally sufficient for a majority of people with Seasonal Affective Disorder, or SAD). But people vary greatly in their sensitivity to light. Some may need more exposure to bright light; others, less. Also, the lower the light intensity (some light boxes emit light at 2,500 lux), the longer your daily therapy sessions will need to be. The goal is to enable more efficient sleep and increase your daytime alertness.

If your main complaint is falling asleep too early, schedule your light therapy in the evening between 7 and 9 p.m. Use the light box on a daily basis to keep your circadian rhythms regular and put off sleep until a reasonable hour.

Do you find that your insomnia varies with the season? If so, when is your insomnia worse?

How to Choose a Light Box